The present invention resides in a system wherein graphics are automatically cut into a sheet of sign material continuously fed through an automated cutting apparatus and more particularly resides in a means and method provided in the system by which the cut sign material sheet is automatically weeded such that portions of the sign material sheet not comprising the cut graphic may be readily peeled away from graphic thus avoiding the practice of hand weeding.
Creating graphics in a web of sign material by cutting into it letters or other shapes has been significantly aided by automated sign generating systems such as disclosed in U.S. Pat. No. 4,467,525 issued to Logan et. al on Aug. 28, 1984, which patent being commonly assigned with the assignee of the present invention. These automated sign making machines permit the rapid composition of sign characters and logos in a variety of fonts, character sizes, spacing, arrangements and appearances selected by the user according to the desired message to be made. Additionally, these machines recall from memory preprogrammed designs directing movements of an automated coordinate controlled cutting tool over the sign material sheet to effect rapid cutting of the desired graphic into the sign material sheet. The designs and letters which comprise the graphic cut into the sign material sheet are not strictly closed shapes, such as found with the letters "J" or "L", but rather involve shapes that have openings cut in them to further define the character or shape being created, such as with the letters "O" or "P". Thus, it becomes apparent that despite the rapidity which these shapes can be cut by the machine in the sign material sheet, mass producing these shapes in final form is nonetheless limited by the hand weeding process.
Hitherto, weeding of sign material from around and within the graphic cut in the sign material sheet was usually done by hand utilizing a pair of tweezers to lift an edge of the material away from a base or liner sheet material on which the sign material sheet is carried. Since the sign material sheet and the base layer are loosely bonded with one another by a layer of low tack adhesive, the process of hand weeding can become particularly tedious especially in light of the very thin sign material sheet thickness which must be separated from the associated base layer. Notwithstanding this, weeding of the unwanted sign material from the cut graphic while the graphic is still bonded to the base layer sheet is necessary in order to allow the component parts of the graphic to be maintained in the same spatial relationship with which they were originally cut. Since the variously different sized and shaped pieces which may comprise a particular graphic are precisely arranged by the machine according to a computerized program, it is important that the original layout of the graphic is not disrupted so that it may subsequently be directly applied to the sign surface in the same spatial relationship in which it was produced by the machine.
It is therefore an object of the present invention to provide an automated weeding system of the type wherein a graphic is automatically cut in a sheet of sign material such that sign material not included as part of the cut graphic is automatically weeded from the underlying base layer thus avoiding manual weeding of the sheet material from in and around the cut graphic.
It is a further object of the present invention to provide an automatic weeding system of the aforementioned type wherein differently sized and shaped graphics may be cut from a sheet of sign material and subsequently automatically weeded regardless of the variations in character shapes or patterns cut into the web.
It is yet a further object of the present invention to provide an automatic weeding system of the aforementioned type wherein the sheet of sign material comprising the cut graphic remains bonded to a base sheet in the same orientation and arrangement as originally cut by the system such that the unwanted sign material is readily removed from within and around the cut graphic by an overlay sheet automatically bonded to the weed portions of the sign material sheet.
A further object of the present invention is to provide a method for automatically weeding portions of the sheet of sign material from the underlying base layer upon which the sign material sheet is bonded by utilizing the vectors responsible for originally cutting the graphic to selectively bond unwanted portions of the sign material sheet with an overlay sheet for subsequent removal of the weed.
Still a further object of the present invention is to provide a method whereby differently sized and shaped graphics formed in the sheet material may be left on the underlying base layer while the remaining non-graphic material is pulled away from the underlying base layer by an overlay sheet provided with means for separating graphic and non-graphic material from the base layer.
Other objects an advantages of the present invention will be apparent from the following description and the drawings and from the appended claims.